Slightly improved questing experience

• Removed some particularly boring quests
• Added a couple of new quests, arguably more interesting than the old ones
• The quests are now more obviously categorized into main quests (i.e. boss fights) and side quests

• Crafted by the Engineer
• Requires Mysterious energy cores to craft, a material that drops from Metal Core

• You can now jump even when the character is slightly above the ground, which makes timing your jumps a bit easier and removes the frustration of your character not jumping when you hit spacebar a couple milliseconds too early.
• Fixed the issue that prevented the character from jumping when moving up or down a "staircase" of blocks.
• Fixed the issue where the character was not taking damage from being inside the map border, which allowed the player to use the teleportation ability to venture outside of the game world.
• Balanced the volume of the cave background music, the later section of the track should no longer be ear-piercingly loud.